Linear compressor

ABSTRACT

The present invention relates to a linear compressor. The linear compressor according to the spirit of the present invention includes a cylinder, a piston, a suction valve, and a valve fastening member. In addition, the suction valve includes a fixed portion and a plurality of vanes extending from the fixed portion in a radial direction and deformed forward in the radial direction to open the suction port. The plurality of vanes includes a first vane and a second vane formed with a lower rigidity or a lower stiffness than the first vane.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 10-2019-0051628, filed on May 2, 2019, in the Korean Intellectual Property Office, the disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND

The present invention relates to a linear compressor.

Generally, a compressor is a mechanical device that increases pressure by receiving power from a power generating device such as an electric motor or a turbine and compressing air, refrigerant, or various other working fluids, and is widely used throughout the industry as well as home appliances such as the refrigerator.

The compressor is classified into a reciprocating compressor, a rotary compressor, and a scroll compressor according to the compression method of the working fluid.

Specifically, the reciprocating compressor includes a cylinder, and a piston provided in the cylinder to be capable of linearly reciprocating. A compression space is formed between the piston head and the cylinder, and the working fluid in the compression space is compressed to high temperature and high pressure while the compression space is increased and decreased by the linear reciprocating motion of the piston.

In addition, the rotary compressor includes a cylinder and a roller that rotates eccentrically in the cylinder. Then, the roller is rotated eccentrically in the cylinder to compress the working fluid supplied to the compression space at high temperature and high pressure.

The scroll compressor also includes a fixed scroll and an orbiting scroll that rotates about the fixed scroll. Then, the orbiting scroll rotates to compress the working fluid supplied to the compression space at high temperature and high pressure.

Recently, among the reciprocating compressors, the development of a linear compressor for directly connecting a piston to a linear reciprocating linear motor has been actively made.

Specifically, the linear compressor is configured to suction, the refrigerant into the compression space while the piston is linearly reciprocated in the cylinder by the linear motor inside the sealed shell, compress, and then discharge. Accordingly, the piston is provided with a suction hole through which the refrigerant flows into the compression space and a suction valve for opening and closing the suction hole.

In connection with such a linear compressor, the present applicant has been registered by carrying out a patent application (hereinafter, referred to as prior reference 1).

-   1. Publication No. 10-2017-0124905 (Publication date: Nov. 13, 2017) -   2. Name of invention: linear compressor

The related art 1 discloses a shape of the suction valve, and the suction valve is provided with a plurality of vanes. Such a vane is provided to correspond to each suction hole and can open and close each suction hole.

At this time, there was a problem that a predetermined noise is generated by the impact that the vane opens and closes the suction hole. In particular, there is a problem that a significant noise occurs while a plurality of vanes open and close the suction hole at the same time.

Since such noise corresponds to a main noise source when the compressor is driven, there is a problem that a great inconvenience for the user using the compressor and the devices equipped with the compressor is generated.

SUMMARY

The present invention has been proposed to solve such a problem, and an object of the present invention is to provide a linear compressor which reduces noise generated through a suction valve formed of a plurality of vanes having different rigidity from each other.

In particular, an object of the present invention is to provide a linear compressor including a suction valve having a different rigidity from each other, as the plurality of vanes are formed in different thicknesses, lengths or widths from each other.

In addition, an object of the present invention is to provide a linear compressor that effectively reduces noise by varying the number of the vanes and the number of suction holes that is opened and closed by the plurality of vanes.

A compressor according to the spirit of the present invention is characterized in that the compressor includes a suction valve provided with vanes having different rigidity from each other.

A linear compressor according to the spirit of the present invention includes a cylinder configured to form a compression space; a piston configured to reciprocate in an axial direction to vary the volume of the compression space, the piston being configured to have a suction port which supplies refrigerant to the compression space; a suction valve configured to be disposed in front of the piston forming the compression space so as to open and close the suction port; and a valve fastening member configured to be inserted into a front surface of the piston through the suction valve so as to fasten the suction valve to the piston.

The suction valve includes a fixing portion which is in close contact with the front surface of the piston by the valve fastening member; and a plurality of vanes which extends from the fixed portion in a radial direction and is deformed forward from the front surface of the piston in the axial direction to open the suction port.

The plurality of vanes include a first vane; and a second vane which is formed with a lower rigidity or a lower stiffness than the first vane.

In detail, the second vane may be 1) extended further in the radial direction, 2) thinner in the axial direction, or 3) narrower in the circumferential direction than the first blade.

At this time, the suction port includes a plurality of suction holes centered on a virtual pitch circle formed on the front surface of the piston and spaced apart in a circumferential direction along the pitch circle.

In other words, the plurality of suction holes are respectively formed along the circumference of one circle (pitch circle).

According to the present invention, the plurality of vanes provided in the suction valve are provided with different rigidity from each other, there is an advantage that the noise generated when the suction hole is opened and closed due to the refrigerant flow can be reduced.

In addition, as the plurality of vanes are provided with different thicknesses, lengths or widths, from each other, it is possible to form a suction valve having different stiffness from each other. Accordingly, there is an advantage that noise can be reduced while reducing the impact sound between the suction valve and the piston.

In detail, vanes having different stiffness from each other have different strain rates or response rates from each other, and thus, the suction holes may be opened and closed at different timings from each other according to the flow of the refrigerant.

Accordingly, there is an advantage that the impact of front surfaces of the vane and the piston is generated at different timings and noise can be reduced.

In addition, by providing the plurality of vanes and the suction hole that is opened and closed by the plurality of vanes in various numbers, there is an advantage that the noise can be effectively reduced according to the design.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating a linear compressor according to an embodiment of the present invention.

FIG. 2 is an exploded view illustrating a shell and a shell cover of the linear compressor according to an embodiment of the present invention.

FIG. 3 is an exploded view illustrating a configuration of a linear compressor according to an embodiment of the present invention.

FIG. 4 is a sectional view taken along line IV-IV′ of FIG. 1.

FIGS. 5 and 6 are views illustrating a piston and a suction valve of the linear compressor according to the first embodiment of the present invention.

FIG. 7 is a front view illustrating the piston of the linear compressor according to the first embodiment of the present invention.

FIGS. 8 to 10 are various views illustrating a suction valve of the linear compressor according to the first embodiment of the present invention.

FIGS. 11 and 12 are views illustrating a piston and a suction valve of the linear compressor according to the second embodiment of the present invention.

FIG. 13 is a front view illustrating a piston of the linear compressor according to the second embodiment of the present invention.

FIGS. 14 to 16 are various views illustrating a suction valve of the linear compressor according to the second embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, some embodiments of the present invention will be described in detail with reference to the accompanying drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are illustrated in different drawings. In addition, in describing the embodiments of the present invention, when it is determined that a detailed description of a related well-known configuration or function interferes with the understanding of the embodiments of the present invention, the detailed description thereof will be omitted.

In addition, in describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the components from other components, and the nature, sequence, or order of the components are not limited by the terms. If a component is described as being “connected”, “coupled” or “accessed” to another component, that component may be directly connected or accessed to that other component, but It is to be understood that another component may be “connected”, “coupled” or “accessed” between each component.

FIG. 1 is a view illustrating a linear compressor according to an embodiment of the present invention, and FIG. 2 is an exploded view illustrating a shell and a shell cover of the linear compressor according to an embodiment of the present invention.

Referring to FIGS. 1 and 2, the compressor 10 according to an embodiment of the present invention includes a shell 101 and shell covers 102 and 103 coupled to the shell 101. In a broad sense, the shell covers 102 and 103 may be understood as one configuration of the shell 101.

Under the shell 101, the leg 50 may be coupled. The leg 50 may be coupled to a base of a product on which the compressor 10 is installed. For example, the product may include a refrigerator, and the base may include a machine room base of the refrigerator. As another example, the product may include an outdoor unit of an air conditioner, and the base may include a base of the outdoor unit.

The shell 101 has a substantially cylindrical shape and may have an arrangement lying in the transverse direction, or an arrangement lying in the axial direction. Referring to FIG. 1, the shell 101 extends in the transverse direction and may have a somewhat lower height in the radial direction. In other words, since the compressor 10 may have a low height, when the compressor 10 is installed in the machine room base of the refrigerator, there is an advantage that the height of the machine room may be reduced.

On the outer surface of the shell 101, a terminal 108 may be installed. The terminal 108 is understood as a configuration for delivering external power to the motor assembly 140 of the linear compressor (see FIG. 3). In particular, the terminal 108 may be connected to a lead wire of the coil 141 c (see FIG. 3).

On the outside of the terminal 108, a bracket 109 is provided. The bracket 109 may include a plurality of brackets surrounding the terminal 108. The bracket 109 may perform a function of protecting the terminal 108 from an external shock or the like.

Both side portions of the shell 101 are configured to be opened. The shell covers 102 and 103 may be coupled to both side portions of the opened shell 101. In detail, the shell covers 102 and 103 include a first shell cover 102 coupled to an opened side portion of the shell 101 and a second shell cover 103 coupled to the other opened side portion of the shell 101.). By the shell covers 102 and 103, the inner space of the shell 101 may be sealed.

Referring to FIG. 1, the first shell cover 102 may be located at the right side portion of the compressor 10, and the second shell cover 103 may be located at the left side portion of the compressor 10. In other words, the first and second shell covers 102 and 103 may be disposed to face each other.

The compressor 10 further includes a plurality of pipes 104, 105, and 106 provided in the shell 101 or the shell covers 102 and 103 to suck, discharge, or inject refrigerant.

The plurality of pipes 104, 105, and 106 include a suction pipe 104 which allows refrigerant to be suctioned into the compressor 10, a discharge pipe 105 which allows the compressed refrigerant to be discharged from the compressor 10, and a process pipe 106 which allows refrigerant to be replenished with the compressor 10.

In one example, the suction pipe 104 may be coupled to the first shell cover 102. The refrigerant may be suctioned into the compressor 10 through the suction pipe 104 in the axial direction.

The discharge pipe 105 may be coupled to an outer circumferential surface of the shell 101. The refrigerant suctioned through the suction pipe 104 may be compressed while flowing in the axial direction. In addition, the compressed refrigerant may be discharged through the discharge pipe 105. The discharge pipe 105 may be disposed at a position closer to the second shell cover 103 than the first shell cover 102.

The process pipe 106 may be coupled to an outer circumferential surface of the shell 101. The worker may inject refrigerant into the compressor 10 through the process pipe 106. The process pipe 106 may be coupled to the shell 101 at a different height than the discharge pipe 105 so as to avoid interference with the discharge pipe 105. The height is understood as a distance in the vertical direction (or radial direction) from the leg 50. Since the discharge pipe 105 and the process pipe 106 are coupled to the outer circumferential surface of the shell 101 at different heights from each other, work convenience can be achieved.

At least a portion of the second shell cover 103 may be adjacent to an inner circumferential surface of the shell 101 corresponding to the point at which the process pipe 106 is coupled. In other words, at least a portion of the second shell cover 103 may act as a resistance of the refrigerant injected through the process pipe 106.

Therefore, at the viewpoint of the flow path of the refrigerant, the flow path size of the refrigerant flowing through the process pipe 106 is formed so as to be reduced by the second shell cover 103 while entering the inner space of the shell 101 and to be increased again while passing through the inner space thereof. In this process, the pressure of the refrigerant may be reduced to vaporize the refrigerant, and in this process, the oil portion contained in the refrigerant may be separated. Therefore, as the refrigerant from which the oil portion is separated flows into the piston 130 (see FIG. 3), the compression performance of the refrigerant may be improved. The oil portion can be understood as the working oil present in the cooling system.

On the inner surface of the first shell cover 102, a cover support portion 102 a is provided. A second support device 185 to be described below may be coupled to the cover support portion 102 a. The cover support portion 102 a and the second support device 185 may be understood as devices for supporting the main body of the compressor 10. Here, the main body of the compressor means a component provided inside the shell 101 and may include, for example, a driving unit for back and forth reciprocating motion and a support portion for supporting the driving unit. The drive unit may include components such as a piston 130, a magnet frame 138, a permanent magnet 146, a supporter 137, and a suction muffler 150 to be described below. The support portion may include components such as resonant springs 176 a and 176 b, a rear cover 170, a stator cover 149, a first support device 165, and a second support device 185, which will be described below.

A stopper 102 b may be provided on the inside surface of the first shell cover 102. The stopper 102 b is understood as a configuration that prevents the main body of the compressor, in particular, the motor assembly 140, from colliding with the shell 101 and being damaged by vibration, shock, or the like generated during transportation of the compressor 10. The stopper 102 b is positioned adjacent to the rear cover 170 to be described below, and when the shaking occurs in the compressor 10, the rear cover 170 interferes with the stopper 102 b, and thus it is possible to prevent the shock from being transmitted to the motor assembly 140. On the inner circumferential surface of the shell 101, a spring fastening portion 101 a may be provided. For example, the spring fastening portion 101 a may be disposed at a position adjacent to the second shell cover 103. The spring fastening portion 101 a may be coupled to the first support spring 166 of the first support device 165 which will be described below. By coupling the spring fastening portion 101 a and the first support device 165, the main body of the compressor may be stably supported inside the shell 101.

FIG. 3 is an exploded view illustrating a configuration of a linear compressor according to an embodiment of the present invention, and FIG. 4 is a sectional view taken along line IV-IV′ of FIG. 1.

Referring to FIGS. 3 and 4, the compressor 10 according to an embodiment of the present invention includes a cylinder 120 provided inside the shell 101, a piston 130 for reciprocating linear motion in the cylinder 120, and a motor assembly 140 as a linear motor imparting a driving force to the piston 130. When the motor assembly 140 is driven, the piston 130 may reciprocate in the axial direction.

The compressor 10 further includes a suction muffler 150 connected to the piston 130 to reduce noise generated from the refrigerant suctioned through the suction pipe 104. The refrigerant suctioned through the suction pipe 104 flows into the piston 130 through the suction muffler 150. For example, in the process of passing the refrigerant through the suction muffler 150, the flow noise of the refrigerant may be reduced.

The suction muffler 150 includes a plurality of mufflers 151, 152, and 153. The plurality of mufflers 151, 152, and 153 include a first muffler 151, a second muffler 152, and a third muffler 153 coupled to each other.

The first muffler 151 is located inside the piston 130, and the second muffler 152 is coupled to the rear side of the first muffler 151. In addition, the third muffler 153 may receive the second muffler 152 therein and may extend to the rear of the first muffler 151. In view of the flow direction of the refrigerant, the refrigerant suctioned through the suction pipe 104 may pass through the third muffler 153, the second muffler 152, and the first muffler 151 in order. In this process, the flow noise of the refrigerant can be reduced.

A muffler filter (not illustrated) may be positioned at an interface at which the first muffler 151 and the second muffler 152 are coupled. For example, the muffler filter may have a circular shape, and an outer circumferential portion of the muffler filter may be supported between the first and second mufflers 151 and 152.

Hereinafter, for convenience of explanation, the direction is defined.

The term “axial direction” may be understood as a direction in which the piston 130 reciprocates, that is, a transverse direction in FIG. 4. In the “axial direction”, the direction from the suction pipe 104 toward the compression space P, that is, the direction in which the refrigerant flows, is referred to as “front”, and the opposite direction thereto is defined as “rear”. For example, when the piston 130 moves forward, the compression space P may be compressed.

On the other hand, the “radial direction” is a direction perpendicular to the direction in which the piston 130 reciprocates, it can be understood in the longitudinal direction of FIG. 4.

The piston 130 includes a substantially cylindrical piston main body 131 and a piston flange 132 extending radially from the piston main body 131. The piston main body 131 may reciprocate inside the cylinder 120, and the piston flange 132 may reciprocate outside of the cylinder 120.

The cylinder 120 is configured to receive at least a portion of the first muffler 151 and at least a portion of the piston main body 131.

Inside the cylinder 120, a compression space P through which the refrigerant is compressed by the piston 130 is formed. In addition, a suction port 133 for flowing a refrigerant into the compression space P is formed at the front portion of the piston main body 131.

In addition, the compressor 10 further includes a suction valve 200 for selectively opening the suction port 133 and a valve fastening member 134 inserted into the piston 130 through the suction valve 200. This will be described in detail after FIG. 5.

In addition, the compressor 10 includes a discharge cover 160 and discharge valve assemblies 161 and 163. The discharge cover 160 is installed in front of the compression space P to form a discharge space 160 a of the refrigerant discharged from the compression space P. The discharge space 160 a includes a plurality of space portions partitioned by the inner wall of the discharge cover 160. The plurality of space portions may be disposed in a front and rear direction and may communicate with each other.

The discharge valve assemblies 161 and 163 are coupled to the discharge cover 160 and selectively discharge the refrigerant compressed in the compression space P. The discharge valve assemblies 161 and 163 include a discharge valve 161 which is opened when the pressure of the compression space P is equal to or higher than the discharge pressure and allows the refrigerant to flow into the discharge space 160 a again and a spring assembly 163 which is provided between the discharge valve 161 and the discharge cover 160 to provide elastic force in the axial direction.

The spring assembly 163 includes a valve spring 163 a and a spring support portion 163 b for supporting the valve spring 163 a to the discharge cover 160. For example, the valve spring 163 a may include a leaf spring. The spring support portion 163 b may be injection-molded integrally with the valve spring 163 a by an injection process.

The discharge valve 161 is coupled to the valve spring 163 a, and the rear portion or the rear surface of the discharge valve 161 is positioned to be supported on the front surface of the cylinder 120. When the discharge valve 161 is supported on the front surface of the cylinder 120, the compression space P maintains a closed state, and when the discharge valve 161 is spaced apart from the front surface of the cylinder 120, the compression space P is opened, and the compressed refrigerant in the compression space P may be discharged.

In other words, the compression space P is understood as a space formed between the suction valve 200 and the discharge valve 161. In addition, the suction valve 200 can be formed at one side of the compression space P, and the discharge valve 161 can be provided at the other side of the compression space P, that is, on the opposite side of the suction valve 200.

In the process of the piston 130 reciprocating linearly inside the cylinder 120, when the pressure of the compression space P is equal to or lower than the suction pressure, the suction valve 200 is opened to suction the refrigerant to the compression space P. On the other hand, when the pressure of the compression space P is equal to or higher than the suction pressure, the refrigerant in the compression space P is compressed in a state where the suction valve 200 is closed.

On the other hand, when the pressure of the compression space (P) is equal to or higher than the discharge pressure, the valve spring 163 a is deformed forward to open the discharge valve 161, the refrigerant is discharged from the compression space P and is discharged to the discharge space of the discharge cover 160. When the discharge of the refrigerant is completed, the valve spring 163 a provides a restoring force to the discharge valve 161 so that the discharge valve 161 is closed.

In addition, a cover pipe 162 a is coupled to the discharge cover 160 to discharge the refrigerant flowing through the discharge space 160 a of the discharge cover 160. For example, the cover pipe 162 a may be formed of a metal material.

In addition, the roof pipe 162 b is further coupled to the cover pipe 162 a to transfer the refrigerant flowing through the cover pipe 162 a to the discharge pipe 105. One side of the roof pipe 162 b may be coupled to the cover pipe 162 a and the other side thereof may be coupled to the discharge pipe 105.

The roof pipe 162 b is made of a flexible material and may be formed to be relatively long. In addition, the roof pipe 162 b may extend roundly from the cover pipe 162 a along the inner circumferential surface of the shell 101 to be coupled to the discharge pipe 105. For example, the roof pipe 162 b may have a wound shape.

The compressor 10 further includes a frame 110. The frame 110 is understood as a configuration for fixing the cylinder 120. In one example, the cylinder 120 may be press fitting to the inside of the frame 110. The cylinder 120 and the frame 110 may be made of aluminum or an aluminum alloy material.

The frame 110 is disposed to surround the cylinder 120. In other words, the cylinder 120 may be positioned to be received inside the frame 110. In addition, the discharge cover 160 may be coupled to the front surface of the frame 110 by a fastening member. The motor assembly 140 includes an outer stator 141 fixed to the frame 110 and disposed to surround the cylinder 120, an inner stator 148 spaced apart from an inside of the outer stator 141, and a permanent magnet 146 positioned in a space between the outer stator 141 and the inner stator 148.

The permanent magnet 146 may linearly reciprocate by mutual electromagnetic forces with the outer stator 141 and the inner stator 148. In addition, the permanent magnet 146 may be composed of a single magnet having one pole or configured by combining a plurality of magnets having three poles.

The permanent magnet 146 may be installed in the magnet frame 138. The magnet frame 138 has a substantially cylindrical shape and may be disposed to be inserted into a space between the outer stator 141 and the inner stator 148.

In detail, with reference to the sectional view of FIG. 4, the magnet frame 138 can be coupled to the piston flange 132, extend in an outer radial direction, and be bent forward. The permanent magnet 146 may be installed in the front portion of the magnet frame 138. Accordingly, when the permanent magnet 146 reciprocates, the piston 130 may reciprocate in the axial direction together with the permanent magnet 146.

The outer stator 141 includes coil winding bodies 141 b, 141 c, and 141 d and a stator core 141 a. The coil winding bodies 141 b, 141 c, and 141 d include a bobbin 141 b and a coil 141 c wound in a circumferential direction of the bobbin. The coil winding bodies 141 b, 141 c, and 141 d further include a terminal portion 141 d for guiding a power line connected to the coil 141 c to be drawn or exposed to the outside of the outer stator 141. The terminal portion 141 d may be disposed to be inserted into a terminal insertion portion provided in the frame 110.

The stator core 141 a includes a plurality of core blocks formed by stacking a plurality of laminations in the circumferential direction. The plurality of core blocks may be disposed to surround at least a portion of the coil winding bodies 141 b, 141 c, and 141 d.

A stator cover 149 is provided on one side of the outer stator 141. In other words, one side portion of the outer stator 141 may be supported by the frame 110, and the other side portion thereof may be supported by the stator cover 149.

The stator cover 149 and the frame 110 is fastened by a cover fastening member 149 a. The cover fastening member 149 a extends forward toward the frame 110 through the stator cover 149 and may be coupled to a fastening hole provided in the frame 110.

The inner stator 148 is fixed to the outer circumference of the frame 110. In addition, the inner stator 148 is configured by stacking a plurality of laminations in the circumferential direction from the outside of the frame 110.

The compressor 10 further includes a supporter 137 supporting the piston 130. The supporter 137 may be coupled to the rear side of the piston 130, and the suction muffler 150 may be disposed in the supporter to pass through the supporter. The piston flange 132, the magnet frame 138, and the supporter 137 may be fastened by a fastening member.

Balance weight 179 may be coupled to the supporter 137. The weight of the balance weight 179 may be determined based on the operating frequency range of the compressor main body.

The compressor 10 further includes a rear cover 170 coupled to the stator cover 149, extending rearward, and supported by the second support device 185.

In detail, the rear cover 170 includes three support legs, and the three support legs may be coupled to the rear surface of the stator cover 149. A spacer 181 may be interposed between the three support legs and the rear surface of the stator cover 149. The distance from the stator cover 149 to the rear end portion of the rear cover 170 may be determined by adjusting the thickness of the spacer 181. The rear cover 170 may be spring-supported to the supporter 137.

The compressor 10 further includes an inflow guide portion 156 coupled to the rear cover 170 to guide the inflow of the refrigerant into the suction muffler 150. At least a portion of the inflow guide portion 156 may be inserted into the suction muffler 150.

The compressor 10 further includes a plurality of resonant springs 176 a and 176 b whose natural frequencies are adjusted to allow the piston 130 to resonate.

The plurality of resonant springs 176 a and 176 b include a first resonant spring 176 a which is supported between the supporter 137 and the stator cover 149 and a second resonant spring 176 b which is supported between the supporter 137 and the rear cover 170. By the action of the plurality of resonant springs 176 a and 176 b, the stable movement of the drive unit reciprocating inside the compressor 10 is performed and it is possible to reduce the vibration or noise generated by the movement of the drive unit.

The supporter 137 includes a first spring support portion 137 a coupled to the first resonant spring 176 a.

The compressor 10 includes a plurality of sealing members 127, 128, 129 a, and 129 b for increasing the coupling force between the frame 110 and the components around the frame 110.

In detail, the plurality of sealing members 127, 128, 129 a, and 129 b include a first sealing member 127 provided at a portion at which the frame 110 and the discharge cover 160 are coupled to each other. The first sealing member 127 may be disposed in the first installation groove of the frame 110.

The plurality of sealing members 127, 128, 129 a, and 129 b further include a second sealing member 128 provided at a portion at which the frame 110 and the cylinder 120 are coupled to each other. The second sealing member 128 may be disposed in a second installation groove of the frame 110.

The plurality of sealing members 127, 128, 129 a, and 129 b further include a third sealing member 129 a provided between the cylinder 120 and the frame 110. The third sealing member 129 a may be disposed in a cylinder groove formed in the rear portion of the cylinder 120. The third sealing member 129 a can perform functions of preventing leakage of the refrigerant in the gas pocket formed between the inner circumferential surface of the frame and the outer circumferential surface of the cylinder to the outside and increasing the coupling force between the frame 110 and the cylinder 120.

The plurality of sealing members 127, 128, 129 a, and 129 b further include a fourth sealing member 129 b provided at a portion at which the frame 110 and the inner stator 148 are coupled to each other. The fourth sealing member 129 b may be disposed in the third installation groove of the frame 110. The first to fourth sealing members 127, 128, 129 a, and 129 b may have a ring shape.

The compressor 10 further includes a first support device 165 coupled to the discharge cover 160 and supporting one side of the main body of the compressor 10. The first support device 165 may be disposed adjacent to the second shell cover 103 to elastically support the main body of the compressor 10. In detail, the first support device 165 includes a first support spring 166. The first support spring 166 may be coupled to the spring fastening portion 101 a described with reference to FIG. 2.

The compressor 10 further includes a second support device 185 coupled to the rear cover 170 to support the other side of the main body of the compressor 10. The second support device 185 may be coupled to the first shell cover 102 to elastically support the main body of the compressor 10. In detail, the second support device 185 includes a second support spring 186. The second support spring 186 may be coupled to the cover support portion 102 a described with reference to FIG. 2.

The cylinder 120 includes a cylinder main body 121 extending in the axial direction and a cylinder flange 122 provided outside the front portion of the cylinder main body 121. The cylinder main body 121 has a cylindrical shape having a central axis in the axial direction and is inserted into the frame 110. Therefore, the outer circumferential surface of the cylinder main body 121 may be positioned to face the inner circumferential surface of the frame 110.

The cylinder main body 121 is provided with a gas inlet 126 into which at least some of the refrigerant discharged through the discharge valve 161 flows. The at least some refrigerant is understood as a refrigerant used as a gas bearing between the piston 130 and the cylinder 120.

The refrigerant used as the gas bearing flows into the gas pockets that are formed between the inner circumferential surface of the frame 110 and the outer circumferential surface of the cylinder 120 via the gas hole 114 formed in the frame 110 as illustrated in FIG. 4. The refrigerant in the gas pocket may flow to the gas inlet 126.

In detail, the gas inlet 126 may be configured to be recessed inward from the outer circumferential surface of the cylinder main body 121 in the radial direction. In addition, the gas inlet 126 may be configured to have a circular shape along the outer circumferential surface of the cylinder main body 121 based on an axial center axis. A plurality of gas inlets 126 may be provided. For example, two gas inlets 126 may be provided.

The cylinder main body 121 includes a cylinder nozzle 125 extending inward from the gas inlet 126 in the radial direction. The cylinder nozzle 125 may extend to the inner circumferential surface of the cylinder main body 121.

The refrigerant passing through the gas inlet 126 flows into the space between the inner circumferential surface of the cylinder main body 121 and the outer circumferential surface of the piston main body 131 through the cylinder nozzle 125. The refrigerant provides a floating force to the piston 130 to perform a function of a gas bearing for the piston 130.

FIGS. 5 and 6 are views illustrating a piston and a suction valve of the linear compressor according to the first embodiment of the present invention.

As illustrated in FIGS. 5 and 6, the piston 130 includes the piston main body 131 which has a substantially cylindrical shape and extends in the front and rear direction and the piston flange 132 which extends outward from the piston main body 131 in the radial direction.

A first piston groove 136 a is formed on the outer circumferential surface of the piston main body 131. The first piston groove 136 a may be located forward with respect to the center line of the piston main body 131 in the radial direction. The first piston groove 136 a may be understood as a configuration provided to guide a smooth flow of the refrigerant gas flowing through the cylinder nozzle 125 and to prevent pressure loss.

In addition, a second piston groove 136 b is formed on the outer circumferential surface of the piston main body 131. The second piston groove 136 b may be located rearward with respect to the center line of the piston main body 131 in the radial direction. In other words, it may be understood that the second piston groove 136 b is disposed between the first piston groove 136 a and the piston flange 132.

In addition, the second piston groove 136 b may be understood as a “discharge guide groove” for guiding the refrigerant gas used for floating of the piston 130 to be discharged to the outside of the cylinder 120. The refrigerant gas is discharged to the outside of the cylinder 120 through the second piston groove 136 b, so that the refrigerant gas used for the gas bearing can prevent from reflowing to the compression space P via the front of the piston main body 131.

The piston flange 132 includes a flange main body 132 a extending outward from a rear portion of the piston main body 131 in the radial direction and a piston fastening portion 132 b further extending outward from the flange main body 132 a in the radial direction.

The piston fastening portion 132 b includes a piston fastening hole 132 c to which a predetermined fastening member is coupled. The fastening member may pass through the piston fastening hole 132 c and may be coupled to the magnet frame 138 and the supporter 137. In addition, a plurality of the piston fastening portions 132 b may be provided, and the plurality of piston fastening portions 132 b may be spaced apart from each other and disposed on an outer circumferential surface of the flange main body 132 a.

The rear portion of the piston main body 131 is opened, and thus the suction of the refrigerant can be made. At least a portion of the suction muffler 150 may be inserted into the piston main body 131 through the rear portion of the opened piston main body 131.

As described above, the piston 130 is provided to be capable of reciprocating in the axial direction, that is, the front and rear direction inside the cylinder 120. In particular, it can be understood that the piston 130 is reciprocated in the axial direction to vary the volume of the compression space P.

At this time, the piston 130 may be understood as a configuration forming the compression space P. In detail, the front surface 131 a of the piston 130 in the axial direction forms the compression space P. In other words, the front surface 131 a is reciprocated by the axial reciprocating movement of the piston 130, and the volume of the compression space P may be varied.

The suction port 133 is formed on the front surface 131 a to supply the refrigerant to the compression space P. The suction port 133 may be understood as a hole formed in the axial direction of the piston 130 to guide the refrigerant to the compression space P.

In addition, a fastening hole 131 b for coupling the suction valve 200 and the piston 130 is formed at the front surface 131 a. The fastening hole 131 b may be understood as a hole into which the valve fastening member 134 is inserted.

The fastening hole 131 b is located at the center portion of the front surface 131 a, and the suction port 133 is located outside the fastening hole 131 b. In detail, the suction port 133 may include a plurality of suction holes, and the plurality of suction holes may be disposed to surround the fastening hole 131 b.

The suction valve 200 is disposed on the front surface 131 a to open and close the suction port 133. In detail, the suction valve 200 may be coupled to the piston 130 by the valve fastening member 134. At this time, a portion of the suction valve 200 is in close contact with the front surface 131 a by the valve fastening member 134, which is referred to as a fixing portion 202.

The fixing portion 202 is provided with a coupling hole 204 through which the valve fastening member 134 passes. The coupling hole 204 may be sequentially arranged in the axial direction with the coupling hole 131 b to form one hole. In addition, as in FIG. 5, in FIG. 6, the valve coupling member 134 passes through the coupling hole 204 and is inserted into the coupling hole 131 b.

In addition, the suction valve 200 includes a plurality of vanes 210 and 220 extending from the fixing portion 202 in the radial direction to open the suction port 133. At this time, the plurality of vanes 210 and 220 may be understood as the remaining portion of the suction valve 200 instead of the fixing portion 202. In other words, the suction valve 200 is divided into the fixing portion 202 and the plurality of vanes.

In addition, the plurality of vanes 210 and 220 correspond to portions deformed forward from the front surface of the piston 130 in the axial direction. In other words, the suction port 133 may be opened as the plurality of vanes 210 and 220 are deformed.

At this time, the compressor 10 according to the spirit of the present invention includes a plurality of vanes 210 and 220 having different rigidity or stiffness from each other. In general, the stiffness represents the degree to which the material resists deformation when elastically deformed. In other words, the plurality of vanes 210 and 220 may be deformed to be different from each other and open the suction port 133.

The plurality of vanes includes a first vane 210 and a second vane 220 formed with a lower rigidity or lower stiffness than the first vane 210. At this time, the low rigidity may correspond to a relative value, and a reference value may not exist. In other words, the low rigidity corresponds to an example of an expression that the first vane 210 and the second vane 220 have different rigidity from each other.

Accordingly, the second vane 220 may be more easily deformed than the first vane 220 by the same external force, in detail, the pressure of the refrigerant. In other words, the second vane 220 may have a higher strain rate or a higher response rate than the second vane 220.

As a result, the first vane 220 and the second vane 220 may open the suction port 133 with a time difference. In detail, the second vane 220 may open the suction port 133 earlier than the first vane 210 and close the suction port later.

This rigidity is proportional to the width and thickness of the vane and inversely proportional to the length of the vane. At this time, the width of the vanes corresponds to the length in the circumferential direction, the thickness of the vanes corresponds to the length in the axial direction, and the length of the vanes corresponds to the length in the radial direction. As a result, the larger the width and thickness of the vane, the higher the mass and the higher the rigidity. On the other hand, the longer the vanes, the farther away from the fixing portion 202, and thus a greater moment is received to reduce the rigidity.

Accordingly, the second vane 220 may be formed in a width extending in the circumferential direction or a thickness extending in the axial direction or in a length extending in the radial direction, than the first vane 210. This will be described below in detail with reference to FIGS. 8 to 10.

FIG. 7 is a front view illustrating the piston of the linear compressor according to the first embodiment of the present invention.

As illustrated in FIG. 7, a virtual pitch circle pc may be formed on the front surface 131 a of the piston 130. At this time, the pitch circle pc means a circle passing through the center of each hole. In addition, the fastening hole 131 b is disposed at the center portion of the pitch circle pc.

The suction port 133 includes a plurality of suction holes formed around the pitch circle pc. In other words, the pitch circle pc corresponds to a circle extending the center of the plurality of suction holes. Since the pitch circle pc is provided as a circle having the same diameter in the radial direction, the plurality of suction holes may be understood to be spaced apart by the same distance from the fastening hole 131 b.

In addition, the plurality of suction holes are spaced apart from each other along the pitch circle pc in the circumferential direction. For example, the plurality of suction holes include the first suction hole 133 a and the second suction hole 133 b and the third suction hole 133 c respectively formed at both sides of the first suction hole 133 a in the circumferential direction. In other words, the second suction hole 133 b, the first suction hole 133 a, and the third suction hole 133 c are sequentially disposed along the pitch circle pc.

At this time, the first suction hole 133 a is disposed closer to the second suction hole 133 b in the circumferential direction than the third suction hole 133 c. In other words, the plurality of suction holes are spaced apart at different intervals from each other in the circumferential direction.

In particular, the plurality of suction holes may be formed in a plurality of pairs. The suction holes formed in pairs are located closer to each other in the circumferential direction than other suction holes. In other words, the first suction hole 133 a and the second suction hole 133 b may be understood as a pair. In addition, a fourth suction hole 133 d which is closest to the third suction hole 133 c in the circumferential direction is provided, and the third suction hole 133 c and the fourth suction hole 133 d may be understood as a pair.

At this time, the pair of suction holes are simultaneously opened and closed by one vane. In other words, one vane can open and close a pair of suction holes. Accordingly, as one vane is deformed, a pair of suction holes are opened, and the refrigerant can flow through the pair of suction holes.

In detail, the first suction hole 133 a and the second suction hole 133 b are simultaneously opened and closed by one of the first vane 210 and the second vane 220. At this time, the third suction hole 133 c may be opened and closed by the other one of the first vane 210 and the second vane 220. In other words, the third suction hole 133 c may be opened and closed by a vane different from the first suction hole 133 a and the second suction hole 133 b.

This may be understood that the third suction hole 133 c is opened and closed separately from the first suction hole 133 a and the second suction hole 133 b. Separately opening and closing may be understood to open or close at different times from each other.

In the above, the common parts of the compressor according to the spirit of the present invention have been described. Therefore, for each embodiment, the above description is cited, and the overlapping description is omitted. Hereinafter, each embodiment will be described in detail.

The suction valve 200 of the linear compressor according to the first embodiment of the present invention is provided with a plurality of first vanes 210 and a plurality of second vanes 220, respectively. In addition, the first vane 210 and the second vane 220 are alternately arranged in the circumferential direction. In other words, the first vanes 210 and the second vanes 220 may be provided in the same number.

Referring to FIGS. 5 and 6, the suction valve 200 includes four vanes. In detail, the suction valve 200 includes two first vanes 210 and two-second vanes 220. Accordingly, it can be seen that the two first vanes 210 and the two-second vanes 220 respectively extend oppositely about the fixing portion 202 in the radial direction.

However, this is merely illustrative and the suction valve 200 may include four or more vanes. For example, the suction valve 200 may include six vanes and may include three first vanes 210 and three-second vanes 220.

As described above, one vane may open and close a pair of suction holes. Accordingly, referring to FIGS. 5 to 7, the suction port 133 may include eight suction holes. In addition, it may be understood that the suction port 133 has four pairs of suction holes. In addition, it can be seen that any two pairs of suction holes are opened and closed by the first vane 210, and the other two pairs of suction holes are opened and closed by the second vane 220.

Hereinafter, a suction valve having a plurality of vanes having different rigidity from each other will be described in detail as an example.

FIGS. 8 to 10 are various views illustrating a suction valve of the linear compressor according to the first embodiment of the present invention. For the convenience of explanation, in FIGS. 8 to 10, the pitch line and the suction hole are illustrated by a dashed-dotted line and a dotted line, respectively, along with the suction valve.

As described above, the second vane 220 has 1) the smaller thickness extending in the axial direction, 2) the longer length extending in the radial direction, or 3) the smaller width extending in the circumferential direction, than the first vane 210.

In FIG. 8, the case of 1), the case of 2) in FIG. 9 and the case of 3) in FIG. 10 are respectively illustrated. The same reference numerals are used for common configurations, and the above descriptions are cited. The different configurations will be identified by attaching a, b, and c to the reference numerals, respectively, and the differences will be described.

As illustrated in FIG. 8, the suction valve 200 a includes a first vane 210 a having a first thickness t1 and a second vane 220 a having a second thickness t2. The first thickness t1 is formed to be thicker than the second thickness t2 (t1>t2). As described above, the thickness corresponds to the axial length.

The suction valve 200 a includes a stepped portion 212 formed between the fixed portion 204 and the first vane 210 a. In other words, the first vane 210 a is formed thicker than the fixing portion 202. In particular, the fixing portion 202 may be formed to the same thickness as the second vane 220 a.

At this time, the fixing portion 202 is illustrated as a portion in close contact with the front surface 131 a by the head portion of the valve fastening member 134.

In detail, the fixing portion 202 is illustrated as a concentric circle having a larger diameter than the coupling hole 204. In addition, portions other than the fixing portion 202 may be defined as vanes or vanes may be defined based on the stepped portion 212. It may be difficult for the fixing portion 202 and the vane to be clearly divided into a portion of the suction valve 200 a.

In addition, the suction valve 200 a may form a step between the second vane 220 a and the fixing portion 202. In other words, the fixing portion 202 and the first vane 210 a may be formed to have the same thickness, and the second vane 220 a may be formed thinner.

At this time, it is assumed that the external conditions of the first vane 210 a and the second vane 220 a except for the thickness are the same. Accordingly, it may be understood that the thicker first vanes 210 a are provided with a higher rigidity than the second vanes 220 a. Accordingly, the first vane 210 a may open the suction port 133 later than the second vane 220 a and close the suction port 133 more quickly.

As illustrated in FIG. 9, the suction valve 200 b includes a first vane 210 b having a first length L1 and a second vane 220 b having a second length L2. The first length L1 is shorter than the second length L2 (L1<L2).

As described above, the length corresponds to the radial length. In detail, it may be defined as the maximum length in the radial direction from the center of the coupling hole 204. In other words, the second vane 220 b is formed to extend longer in the radial direction from the fixing portion 202 than the first vane 210 b.

In particular, the first vane 210 b and the second vane 220 b are formed to extend further outward in the radial direction than the pitch circle pc to cover the suction port 133. At this time, the second vane 220 b may be understood to extend further outward of the pitch circle pc in the radial direction than the first vane 210 b.

At this time, it is assumed that the external conditions of the first vane 210 b and the second vane 220 b except for the length are the same. Accordingly, it may be understood that the second vane 220 b formed longer than the first vane 210 b is provided with lower rigidity than the first vane 210 b. Accordingly, the second vane 220 b may open the suction port 133 more quickly than the first vane 210 b and close the suction port 133 later than the first vane 210 b.

As illustrated in FIG. 10, the suction valve 200 c includes a first vane 210 c having a first width W1 and a second vane 220 c having a second width W2. The first width W1 is larger than the second width W2 (W1>W2).

As described above, the width corresponds to the length in the circumferential direction. In detail, the width may be defined as a length covering the periphery of the pitch circle pc. In other words, the first vane 210 c is formed to cover the periphery of the pitch circle pc more broadly than the second vane 220 c.

In particular, the first vane 210 b and the second vane 220 b are gradually wider in the circumferential direction from the fixing portion 202 toward the outside in the radial direction. At this time, the first vane 210 c may be understood to be gradually widened in the circumferential direction at a larger ratio than the second vane 220 c.

At this time, it is assumed that the external conditions of the first vane 210 c and the second vane 220 c except for the width are the same. Accordingly, it may be understood that the first vane 210 c formed wider is provided with a higher rigidity than the second vane 220 c. Accordingly, the first vane 210 a may open the suction port 133 later than the second vane 220 a and close the suction port 133 more quickly.

In FIGS. 8 to 10, the thickness, the length, and the width are respectively illustrated and described. However, such embodiments may optionally be used together and are not limited to one.

For example, the second vane may have a smaller width and thickness than the first vane. In addition, the second vane may be formed to have a smaller width and a longer length than the first vane. In addition, the second vane may be formed thinner and longer in length than the first vane. In addition, the second vane may have a smaller width and thickness and a longer length than the first vane.

FIGS. 11 and 12 are views illustrating a piston and a suction valve of the linear compressor according to the second embodiment of the present invention, and FIG. 13 is a front view illustrating a piston of the linear compressor according to the second embodiment of the present invention.

In the suction valve 300 of the linear compressor according to the second embodiment of the present invention, the first vane 310 and the second vane 320 are provided in different numbers. In other words, the suction valve 200 according to the first embodiment has an even number of vanes, but the suction valve 300 according to the second embodiment has an odd number of vanes. Hereinafter, only the differences from the first embodiment will be described in detail, and common parts are referred to the above description.

For example, the suction valve 300 may have three vanes and may include one first vane 310 and two-second vanes 320. In addition, one-second vane 320 and two first vanes 310 may be provided.

In addition, a plurality of first vanes 310 and a plurality of second vanes 320 may be provided, respectively. Referring to FIGS. 11 and 12, the suction valve 300 includes five vanes. In detail, the suction valve 300 includes two first vanes 310 and three-second vanes 320. In addition, the suction valve 300 may include three first vanes 310 and two-second vanes 320.

However, this is merely illustrative and the suction valve 200 may include five or more vanes. For example, the suction valve 200 may include seven vanes, and the first vane 210 and the second vane 220 may include three or four vanes.

As described above, one vane may open and close a pair of suction holes. Accordingly, referring to FIG. 13, the suction port 133 may include ten suction holes. In addition, the suction port 133 may be understood that there are five pairs of suction holes.

At this time, as described with reference to FIG. 7, the suction port 133 includes a first suction hole 133 a, a second suction hole 133 b, and a third suction hole 133 c. In FIG. 13, the separation distance between the first suction hole 133 a and the third suction hole 133 c in the circumferential direction is shorter than that in FIG. 7. This can be understood as a natural result of the increase in the number of suction holes.

FIGS. 14 to 16 are various views illustrating a suction valve of the linear compressor according to the second embodiment of the present invention. For the convenience of explanation, in FIG. 14 to FIG. 16, pitch lines and suction holes are illustrated with dashed-dotted lines and dashed lines, respectively, along with suction valves.

As described above, the second vane 220 can have 1) the smaller thickness extending in the axial direction, 2) the longer length extending in the radial direction, or 3) the smaller width extending in the circumferential direction, than the first vane 210.

In FIG. 14, the case of 1), the case of 2) in FIG. 15 and the case of 3) in FIG. 16 are respectively illustrated. The same reference numerals are used for common configurations, and the above descriptions are cited. The different configurations will be identified by attaching a, b, and c to the reference numerals, respectively, and the differences will be described.

As illustrated in FIG. 14, the suction valve 300 a includes a first vane 310 a having a first thickness t1 and a second vane 320 a having a second thickness t2. The first thickness t1 is formed to be thicker than the second thickness t2 (t1>t2). As described above, the thickness corresponds to the length in the axial direction.

In addition, the suction valve 300 a includes a step portion 312 formed between the fixed portion 204 and the first vane 310 a. In other words, the first vane 310 a is formed thicker than the fixing portion 202. In particular, the fixing portion 202 may be formed to the same thickness as the second vane 320 a.

At this time, it is assumed that the external conditions of the first vane 310 a and the second vane 320 a except for the thickness are the same. Accordingly, it may be understood that the thicker first vanes 310 a are provided with a higher rigidity than the second vanes 320 a. Accordingly, the first vane 310 a may open the suction port 133 later and close the suction port 133 sooner, than the second vane 320 a.

In addition, the suction valve 300 a includes three first vanes 310 a and two-second vanes 320 a. At this time, the number of the first vane 310 a and the second vane 320 a may be provided differently according to the design. As the suction valve 300 a includes more first vanes 310 a having a relatively high rigidity, stability can be achieved.

As illustrated in FIG. 15, the suction valve 300 b includes a first vane 310 b having a first length L1 and a second vane 320 b having a second length L2. The first length L1 is shorter than the second length L2 (L1<L2).

As described above, the length corresponds to the length in the radial direction. In detail, the length may be defined as the maximum length in the radial direction from the center of the coupling hole 204. In other words, the second vane 320 b is formed to extend longer in the radial direction from the fixing portion 202 than the first vane 310 b.

In particular, the first vane 310 b and the second vane 320 b are formed to extend further outward than the pitch circle pc in the radial direction to cover the suction port 133. At this time, the second vane 320 b may be understood to extend further outward of the pitch circle pc than the first vane 310 b in the radial direction.

At this time, it is assumed that the external conditions of the first vane 310 b and the second vane 320 b except for the length are the same. Accordingly, it may be understood that the second vane 320 b formed longer than the first vane 310 b is provided with low rigidity. Accordingly, the second vane 320 b may open the suction port 133 faster and close the suction port 133 later than the first vane 310 b.

In addition, the suction valve 300 b is provided with three-second vanes 320 b and two first vanes 310 b. In other words, the suction valve 300 b may further include a relatively low rigidity second blade 320 b to secure a flow amount of the refrigerant.

As illustrated in FIG. 16, the suction valve 300 c includes a first vane 310 c having a first width W1 and a second vane 320 c having a second width W2. The first width W1 is larger than the second width W2 (W1>W2).

As described above, the width corresponds to the length in the circumferential direction. In detail, it may be defined as a length covering the periphery of the pitch circle pc. In other words, the first vane 310 c is formed to cover the circumference of the pitch circle pc more widely than the second vane 320 c.

In particular, the first vane 310 b and the second vane 320 b are gradually wider in the circumferential direction from the fixing portion 202 toward the outside in the radial direction. At this time, the first vane 310 c may be understood to be gradually widened in the circumferential direction at a larger ratio than the second vane 320 c.

At this time, it is assumed that the external conditions of the first vane 310 c and the second vane 320 c except for the width are the same. Accordingly, it may be understood that the first vane 310 c formed wider than the second vane 320 c is provided with a higher rigidity than the second vane 320 c. Accordingly, the first vane 310 a may open the suction port 133 later and close the suction port 133 sooner than the second vane 320 a.

In FIGS. 14 to 16, thicknesses, lengths, and widths are respectively illustrated and described. However, such embodiments may optionally be used together and are not limited to one.

In addition, as in the first and second embodiments, the number of vanes and suction holes may be formed differently according to the design. As described above, by providing a plurality of vanes having different stiffness, the impact sound is generated with a time difference can effectively reduce the noise.

EXPLANATION OF REFERENCE NUMERALS 10: compressor 130: piston 133: suction hole 134: valve fastening member 200: suction valve 202: fixed portion 210, 310: first vane 220, 320: second vane pc: pitch line T: thickness (length in axial direction) L: Length (length in axial W: Width (length in circumferential direction) direction) 

What is claimed is:
 1. A linear compressor comprising: a cylinder that defines a compression space; a piston configured to, based on reciprocating in an axial direction relative to the cylinder, vary a volume of the compression space, the piston defining a suction port configured to supply refrigerant to the compression space; a suction valve disposed forward of a front portion of the piston facing the compression space and configured to open and close the suction port; and a valve fastening member that is inserted into a front surface of the piston through the suction valve and that fastens the suction valve to the piston, wherein the suction valve comprises: a fixing portion that is in contact with the front surface of the piston and that is fastened to the piston by the valve fastening member, and a plurality of vanes that extend from the fixed portion in a radial direction of the piston and that are configured to deform forward from the front surface of the piston in the axial direction to thereby open the suction port, wherein the plurality of vanes comprise: a first vane having a first stiffness and a first rigidity, and a second vane having a second stiffness and a second rigidity, and wherein the second stiffness is less than the first stiffness, or the second rigidity is less than the first rigidity.
 2. The linear compressor of claim 1, wherein the suction port comprises: a plurality of suction holes that are arranged about a center of a virtual pitch circle defined at the front surface of the piston, the plurality of suction holes being spaced apart from one another in a circumferential direction of the piston along the virtual pitch circle.
 3. The linear compressor of claim 2, wherein the plurality of suction holes comprises: a first suction hole; and a second suction hole and a third suction hole that are respectively defined at both sides of the first suction hole in the circumferential direction, and wherein the first suction hole is disposed closer to the second suction hole than to the third suction hole in the circumferential direction.
 4. The linear compressor of claim 3, wherein one of the first vane or the second vane is configured to open and close both of the first suction hole and the second suction hole, and wherein the other of the first vane or the second vane is configured to open and close the third suction hole separately from the first suction hole and the second suction hole.
 5. The linear compressor of claim 1, wherein a thickness of the second vane in the axial direction is less than a thickness of the first vane in the axial direction.
 6. The linear compressor of claim 5, wherein the suction valve further comprises: a stepped portion defined between the fixed portion and the first vane, the thickness of the first vane being greater than a thickness of the fixed portion in the axial direction.
 7. The linear compressor of claim 1, wherein the first vane extends outward of the fixing portion in the radial direction by a first length, and wherein the second vane extends outward of the fixing portion in the radial direction by a second length that is greater than the first length.
 8. The linear compressor of claim 7, wherein the suction port comprises: a plurality of suction holes that are arranged about a center of a virtual pitch circle defined at the front surface of the piston, and wherein the first vane and the second vane extend outward of the virtual pitch circle in the radial direction to thereby cover the plurality of suction holes.
 9. The linear compressor of claim 1, wherein the first vane is wider than the second vane in a circumferential direction of the piston.
 10. The linear compressor of claim 9, wherein circumferential widths of the first vane and the second vane respectively increase as the first vane and the second vane extend outward from the fixing portion in the radial direction.
 11. The linear compressor of claim 1, wherein the suction port comprises: a plurality of suction holes that are arranged about a center of a virtual pitch circle defined at the front surface of the piston, and wherein the first vane covers a first portion of a periphery of the virtual pitch circle, and the second vane covers a second portion of the periphery of the virtual pitch circle, a length of the first portion being greater than a length of the second portion.
 12. The linear compressor of claim 1, wherein: a circumferential width of the second vane is less than a circumferential width of the first vane in a circumferential direction of the piston; an axial thickness of the second vane is less than an axial thickness of the first vane in the axial direction; or a radial length of the second vane is greater than a radial length of the first vane in the radial direction.
 13. The linear compressor of claim 1, wherein the first vane comprises one or more first vanes, and the second vane comprises one or more second vanes, and wherein a number of the one or more first vanes and a number of the one or more second vanes are different from each other.
 14. The linear compressor of claim 1, wherein the first vane comprises a plurality of first vanes, and the second vane comprises a plurality of second vanes, and wherein a number of the first vanes and a number of the second vanes are different from each other.
 15. The linear compressor of claim 1, wherein the suction port comprises a plurality of pairs of suction holes, wherein the first vane is configured to open and close a first pair of suction holes among the plurality of pairs of suction holes, and wherein the second vane is configured to open and close a second pair of suction holes among the plurality of pairs of suction holes, the second pair of suction holes being different from the first pair of suction holes.
 16. A linear compressor comprising: a cylinder that defines a compression space; a piston configured to, based on reciprocating in an axial direction relative to the cylinder, vary a volume of the compression space; a suction port defined in a front surface of the piston and configured to guide refrigerant to the compression space; and a suction valve coupled to the front surface of the piston in the axial direction, the suction valve comprising a plurality of vanes that extend in a radial direction of the piston and that are configured to move in the axial direction to thereby open and close the suction port; wherein the suction port comprises a plurality of suction holes that are arranged about a center of a virtual pitch circle defined at the front surface of the piston, the plurality of suction holes being spaced apart from one another along the virtual pitch circle in a circumferential direction of the piston, wherein the plurality of vanes comprises a first vane and a second vane, and wherein: a circumferential width of the second vane is different from a circumferential width of the first vane in the circumferential direction, an axial thickness of the second vane is different from an axial thickness of the first vane in the axial direction, or a radial length of the second vane is different from a radial length of the first vane in the radial direction.
 17. The linear compressor of claim 16, wherein the first vane comprises a plurality of first vanes, and the second vane comprises a plurality of second vanes, and wherein the first vanes and the second vanes are alternately arranged along the circumferential direction.
 18. The linear compressor of claim 16, wherein the first vane comprises a plurality of first vanes, and the second vane comprises a plurality of second vanes, and wherein a number of the first vanes and a number of the second vanes are different from each other.
 19. The linear compressor of claim 16, wherein the suction valve further comprises a fixing portion that is in contact with the front surface of the piston and that is disposed at a position corresponding to the center of the virtual pitch circle, wherein the plurality of vanes extend from the fixed portion outward in the radial direction, and wherein a circumferential width of each of the plurality of vanes increases in the circumferential direction as the plurality of vanes extend in the radial direction.
 20. The linear compressor of claim 16, wherein: the circumferential width of the second vane is less than the circumferential width of the first vane in the circumferential direction; the axial thickness of the second vane is less than the axial thickness of the first vane in the axial direction; or the radial length of the second vane is greater than the radial length of the first vane in the radial direction. 